SURVIVORSHIP OF CEMENTED JRI TOTAL HIP REPLACEMENT WITH METAL BACKED ACETABULUM

Abstract

The JRI cemented total hip replacement consisted of an acetabulum with a gamma irradiated UHMW polyethylene cup encased in a titanium metal shell, a 32 mm titanium head, and forged titanium alloy stem. Revision of this implant for failure, in particular that of the acetabulum, and the lack of published survivorship prompted a retrospective review of the local series. Data was compiled from theatre log books, patient records and X-rays.

During the period 1989–1997 a single surgeon performed 304 total hip replacements using this JRI prosthesis through an anterior lateral approach. The average age was 70 (48–96), with 186 (61%) female and 85% performed for osteoarthritis. Complete data was available in 236 cases to allow further analysis. The average follow up was 9.3 (1–17) years. During this period 37 hips had to be revised: 28 for a loose acetabulum, both components were loose in 5, and 3 had revision for infection. The mean time to revision was 7.4 (1–17) years.

This data provides a revision rate of at least 16% at ten years. This data does not take potential earlier radiographic failure nor patient function into account. This prosthesis therefore fails to comply with modern benchmarks for survivorship of implants. Furthermore this study highlights the importance of ongoing review of patients who have undergone joint replacement, in particular those with implants that have problems with design, as has been demonstrated in other metal backed components.